Fuel pump



March 1 7, l 925- 1,530,248 J. E. DOUGLAS FUEL PUMP Filed June 6. 1923 3 Sheets-Shoot l March 17, 1925.

. J. E. DOUGLAS FUEL PUMP I Filed June 6, 1923 5 SheetsSheot 2 y mm L: Jazzglmr March 17, 1925. 1,530,248

J.- E. DOUGLAS FUEL PUMP Filed Juan 6. 1923 3 Sheets-Shoot 5 Patented Mar. 17, 1925.

5 TA PA new e ent- 0E.

JOHN ERLE noUGLAs; 0Fmitmwennmannniemwn Assm noaf r oaivinmeimensrme CUMPKN YQ-OF IBiHMIN-GHAM;ALABAMA, I A oonronramon on ALABAMA.

Application ttled June 6,

To all whom it may convent I Be it knownthat {1, 'Joi-Iir ERI'JE DOUGLAS, a citizen of the I BirIninghann-in the county "of Jefferson and State of Alabama, have invented certain new and useful Improvements in Fuel Pumps and I; do hereby- 'decl-arefthe following to be a full, clear,' andeiiaet" desefipti'o'n of the invention,-such asWillenahlebtliers skilled in, tl1e--art to 'vvhih it appertains to make and-use the'saine.

The present invention relates to improvements in injecti0n1pu1npsf6r' iiselpart ic'iilarly Witli'vDiesel 'or the likev internal combustion crude oil a engines,- and the invention has for an ohject'to secure" the inj'etieiro'f the fuel at constantupressure irresp ctiv ofthe load upon'the motor andtob'etter obtain'a spraying of the fuel at the fuelno'aZ'le-at greatly increasedlpressure resulting int'he more perfect atomization at all speeds.

Another object of the invention 'li'es in providing an im roved -ii'ijeetion-Icpii'iiip in which the inoy'ingljpart-s Will'beluhricated by the "fuel oil "under pressure the pump being so 2 packed as "to "avoid" the leakage of fuel even at' higlnpressnre. 4

i X further ohjectfo flthe invention is 'to provide I an improved inj action Lpump a'ctu ated'eonti'nuously during" the running of'tlie motor and operating to draw from the fuel tank and circulate the "fnel at' allaimes, there bei g an a-iito'mati'c eontroltle-vice associate'd' with the; pump and With the engine governor for determi'n'ingthe amount of fuel to he clli'veredto the nozzle i'nfthe cylinder head and'hringing an equalaino'untof fuel from the fneltan'k. 7

With the foregoing and *other objects in View, the invention will'be more fully described he einafter, and *Willbe more particularly. pointedout in the'claims appended hereto; I V I In the -drawings, wherein like symbols refer to like or c'orrespondingl parts' through out' the several'view's, V

Figure 1 is a side iew of a crude oil en'-' gine havingthe improvedpump' and asso-' ciated parts-constructed and operating ac-i cording to the;present-inyention- Figure 2 is an enlarged longitudinal section taken through the pump. 7

Figure 3is' anenlarged fragmentary side View, With parts s the pump andaeljncent parts.

"United states, resfding at hownin section showing 7 I consequence to minimize Wear and facilitate 110 12523. Serial No; 1643,?16.

' Fi'gu re "14-: is afsin'iila'r view taken" from the opposite "side of the pump.

' "Figure "5 {isamend View (if the pnmpnnd its alliedniechanisnnand H y Figure e is a sectiontaken' err line i- 6 in Figure'a. j

Referring inore'oparticiila'rly to thedrawings; lgclesignatesflin general an internal combustion crude oii'haVy oil 'engine of the Dieseloroth'er t y'pfle' in'w11if 1"2 is "the'eran'k shjaft andfi thefcylinder. The fuelta'iik is indicated "hy'the line 4 and is iii-connection with a f'uel 'eut'let pipe?) l'ea dingtio thepmn' casing" 6. Fro the pnnipeasing'the fuel previously 'liftedf'throngh' "the pipe 5 is forced into'the del-iyeryp'ip'e b'yWhichit is conveyed to the nozzle which sprays 'it' into the combustion chamber "in the head of the cyli'nderfi. The general operation of'an engine of-this cha'racte'r'is welljknown" and such engines are usually: equipped with governo'rs of the centrifugal type i n which 10 designates the centrifugal balls carried by the outwardly "movable arms "11 secured to the verticall'y movj able "ring ,12 which is adapted to "raise and lower the shaft 13 in accordance Witlrthe speed off the engine; the

governor being driven "from 'the'crank shaft 2 "for instance by a belt 1 4301 other associated mechanical transmission;

The improved pump isconstructed more particularly as illustrated in Figure '2 in Which'tlie casing Gis shown t0 contain two superimposed. and longitudinally extending cylinders 15 and- 16, the lower cylinder-dieing preferably situated close 'tothe 'base of .the casi-ng whi'le the upper cylinder issituated approximately ini'dway the height of the same or slightly ahovethe centerlin'e. In the cylinders are plungers 17 and 18 cutaway i at their rear ends and [providedf with rack teeth 19 and 20 disposed mutually t0- ward one another in order to be engaged alikeby'the-teeth upon a Vilerating"pinion 20 carried upon a shaft 21 transversely journale'd through the casing between the two cylinders 15 and 16. The rack teeth 19 and; 20 are disposed substantially coincident with the axis of theiplungers 17 and 18in order to insure that the thrust developed by the movement of the: pinion transmitted centrallyand equally to avoid jamming of the plungers in the cylinders or undue friction upon'the Walls thereof and as a the free action of the pump. At one end of the block or casing 6 are plugs 22 and 23 screwed into the ends of the cylinders to enable access to be had thereto for the purpose of cleaning or removing the plungers.

The pipe 5 conveying oil from the oil tank 4 is connected to the pipe section 24 projecting from the lower forward portion of the pump casing 6, in which pipe section is a seat for the downwardly seating check valve 25 having the perforated guard plate 26 thereabov-e communicating directly with the open end of the lower cylinder 15. A vertically disposed threaded opening 27 is made in the pump casing or block 28 containing also a similarly downwardly seating check valve 29 communicating at its under side with the open end of the lower cylinder 15. This block communicates with a transverse passage 31 leading to the open adjacent end of the upper pump cylinder 16 and to the pipe 8 which delivers the fuel to the nozzle, the pipe being provided with a screw threaded connection 32 by which it is secured in fluid-tight fashion to the casing.

The valve 29 is carried by a stem 30 extending upwardly and guided at its upper end in a cap 33 threaded into the top of the casing. The stem is provided with a shoulder or flange 34 against the upper edge of which a coil spring 35 engages in the act of forcing yieldably the valve 29 to its seat. A lifting arm 36 straddles a reduced part of the valve stem 30 beneath the flange 34, said lifting arm being fast on a shaft 38 journaled transversely in the casing and projecting at one end, as seen in Figure 4, to receive an arm 39.

The arm 39 projects above the shaft 38 to which it is fixed and is pivotally coupled to a link 41 having at its free end, a yoke 42 occupied by a tapering or wedge shaped bar depending from the governor shaft 13 and pivoted thereto as indicated at 44 in Figures 1 and 5 in order that the bar may swing in the same direction with the link 41 and in the direction of the slot in the yoke which also contains a finger 45 projecting upwardly from a rock shaft 46 extending transversely through the casing and having a continuous oscillating movement imparted by the moving parts of the engine. The finger 45 is so disposed that it bears against one wedgeshaped side face of the bar, while the bar engages against the end of the yoke. An appropriate guide may be provided for the yoke and link 41.

The bar carried by the governor may be of the same shape as in my coopending application filed April 18, 1923, Serial No. 633037 or it may be as shown herein where the bar is indicated at 43 having a lower cut-out portion slidingly receiving a wedge 7 carried by an arm 37 pivoted to the bar and held under the pressure of a spring 37' by which the wedge 7 is normally held down. A cord is attached to the arm 37. for drawing the wedge up.

One mechanism for securing the reciprocation of the pump plungers and also the oscillation of the rock shaft 46 is illustrated in Figures 1 and 3 in which an eccentric 50 upon the crank shaft 2 is utilized to move the eccentric strap 51 and also this eccentric strap the arm 52 secured thereto and lying along one side of the pump casing 6. At its free end this arm 52 is slotted as indicated at 53 receiving therein a pin 54 which projects from an arm 55 upstanding from the pump shaft 21 upon which the pump pinion is mounted. Upon this same shaft 21 is an eccentric 55 having a strap secured to an arm 56 which is pivotally coupled as indicated at 57 to a depending arm 58 upon therock shaft 46.

At 60 is shown a by-pass about the valve 29. At the base of the by-pass is a check valve 61 operating toward and from a seat 62 and urged to a closed position by a coil spring 63. The check Valve may be a unit assembly inserted and removed through use of the plug 64.

In operation, as the engine shaft 2 rotates it will revolve the governor balls 10 and also reciprocate the rod 52 by which an oscillating movement is communicated through the arm 55 and shaft 21 to the pinion 20. Due to the gear connection between the pinion and the plungers 17 and 18, the latter will be reciprocated in the cylinders 15 and 16 but the plungers will move in constantly relatively reverse directions. When for instance the lower plunger 17 is moving to the right in Figure 2, the upper plunger 18 is moving to the left.

The plunger 17 draws oil from the fuel tank on its back stroke. l/Vhen the plunger 17 goes forward the fuel in front of it is caused to open the check valve 29 against spring pressure and the fuel passes into the space in front of the receding plunger 18. When the top plunger is caused to displace the fuel in front of'it the oil must go through the pipe 8 to the nozzle until the check valve 29 is opened mechanically by: the governor controlled mechanism. That is, the governor controls the mechanical opening of the valve 29 against pressure in the top cylinder. As soon as the valve 29 is mechanically opened, the fuel in front of the plunger 18 is bypassed in front of the plunger 17. As soon as the valve 29 is opened mechanically, the valve 25 closes and no more fuel is drawn from the tank. This causes the plunger 17 to draw only the amount of fuel from the tank that the plunger 18 is injecting into the engine through the nozzle.

The relief valve 61 is held closed by a lithe wedge 7 back'totheirformer position ger a5 ins-some poweriurs rin Therelif valve 6145 (any opened when an 'e'xtreme pretletenninsd "pressure is built up in the upper 63 nder.

The pressare neeessary to open relief "valve til is much greater-thaneliarneeessaryito inject "the oil th'i 'oughit-he nozzie aud is only attained vlien'=sonie ob's'tru io'n is for1ned I in the nozzle. If we uid ner havethe felief engine independent -of go'vernor control;

The arm is attached to the governor stem in the usual manner. "Whenitis desired to speed up the engine a' cord orwire -atta'ched to the link 37' is pulled, causing the wedge 7 to be raised and allowing more 1 fuel 'to "go lnt'othe engine because of the-relativel later mechanical opening of the valve-"- 29. \Vhenthe tensionon thew-ire o'r cord is slackened' the spring bri ngs the link 37 and and puts theengine "back under the control of the governor.

If the fingeraawas connected to the "yoke 41,1031 means of a pin, thevalve between the upper and lower cylinder wouldbe in to open as soon astlie upper piston started its ower stroke. Naturally in this case no fuel 7 would be injeote'd}througlr' the nozzle. Now if this pin were a loose fit so that the action of lifting the valve la 'ged-be'hind the action b of the top 1 piston, the oil displaced by the top piston during'this time of lagging action would beforced through the nozzle and, as soon as the lost 'motion between pin and hole 'weretaken up and valve opened,

the balance of theoil displaced by thetop plunger would travel around under the valve.

We arsasing a wedge instead' of a pin. V hen the wedge is lowered to the point where it just fits the space between the fin- V and the yoke 41, when the finger 45 is at its farthest back position, any movement of the finger 45 will lift the valve off its seat. This case is similar to that described if the finger and yoke were pinned together. Any lifting of the wedge will allow action of the yoke to lag behind the action of the finger and we have a condition similar to a pin in a loose hole, some oil will be forced through the nozzle.

We, therefore, see that the amount of oil injected per stroke of the pump is deter mined by the amount of lost motion or lag between the action of the finger and yoke. As the action of the finger is controlled by the rotation of, the crank shaft, we can measure this lost motion or lag in degrees of rotation of the crank shaft.

hen the engine speeds up, the governor lowers the wedge, the amount of lost motion between the finger and yoke is reduced,

sai'd pun ips from the initial toward the final pump,-and I there isless "lag between the -forward anotion of thefinger and the yoke, and a sma l'ler amount of the oil in front of the; plunger 'is forced through the nozzle because fuel is forced through the nozzle "during "a sinal ler degree ofrotationbfthe erank shaft. In

other words, the mgove'rn'or controls the amount of fuel supplied I to the engine by reducing or inereaslng the angle" of rotation of the engine during which injection =ta=ks place;

It is i obvious i that vari'ous changes -and modifications-inaybe in-ade in the' details of construction and design ='of the above specificaily described "em-loo'dime'nt'' of this invention without"departing thereof; such changes and modifications being restricted" only by the scope of the *following claims.

WVhat is claimed is'z fuel pump comprising aninLit-ial pump-for drawing the fuel from-a-sourceof supply,-'a. final pump for drawing the charge of fuel' from the initial pump and-supj'alyi-ng same t'othe motor, a check valve disposed between said pumps for preventing backflowyand means to; positively open sa-i dcheck valve despite the pressure in the "final-pump. An improved'fuel pump comprising-an initialpump for withdrawing a chargeo fuel froma- 'source of supply, afinal-pump for drawing said charge from the initial pump and for circulating theehange-to the combustion chamber of the n'1otor,--a.yiel'dably closed and adapted to permit flow only I check valve-proportionately to the speed of'the engine.

means for. positively opening sa d initial pump,= a final pump in communication therewith, a spring-pressed check valve disposed between said pumps, means for positively opening and holding open said check valve whereby to permit the final pump to return its charge to the initial pump for drawing in fresh charges, and governing means on the engine connected to said check valve opening means whereby to open the checkvalve proportionately to the speed of the engine.

4. In combination with an internal combustion engine, and a governor driven thereby, a pair of communicating pumps, one of said pumps being in communication with a source of fuel supply and the other pump being in communication with the combustion chamber of the engine, a check valve disposed between said pumps, means for positively opening said check valve, said means being coupled to the governor and actuatedproportionately to the speed of the engine, and means associated with said valve opening means for varying the lifting of check valve disposed between An improved fuel; pump comprising an theva-lve independently of the action of the governor. z

5. In combination with an internal combustion engine, and a governor therefor, a pair of communicating pumps, a check valve controlling the communication between said pumps one of said pumps being in communication with a source of fuel supply and the other pump being in communication with the motor, means for independently and positively lifting said check valve from its seat, said means being driven from the engine, control means for said last named means coupled to said governor, and movable therewith on variations in speed of the engine, and a hand actuated device associated with said last named means for controlling the throw of the valve lifting means independently of the action of the governor.

6. A pump comprising initial and final chambers in communication respectively with a source of fuel supply and with an internal combustion engine, said chambers being in communication, alternately acting plunger-s in said chambers, a yieldably closed check valve controlling the communication between said chambers, a rock lifting arm for positively moving said check valve over its seat, a reciprocating yoke coupled to actuate said arm, an adjustable governor arm extending into said yoke, a shift-able wedge carried by said governor arm, and means for operating in said yoke and in conjunction with said arm and wedge to reciprocate the yoke variably dependent on the adjustment of said governor bar and the wedge.

7. A pump comprising a casing having adjoining and communicating chambers disposed in communication, alternately acting plungers in said chambers, a yieldably closed check valve between said chambers, means for positively lifting said check valve from its seat and a by-pass between said chambers.

8. A fuel pump comprising a casing having adjoining and communicating chambers, alternately acting plunger therein, a yieldably closed check valve controlling the com-- munioa-tion between said chambers, a bypass about said check valve, a relief valve in said bypass and means for POSltlVBlf/ opening said check valve. 7

9. A fuel pump comprising in combination with an internal combustion engine, a pump casing having pump cylinders, plungers therein, a gear to operate the plungers, an arm connected to the gear, an eccentric turned by the engine, and an eccentric rod having a loose connection with said arm whereby the mid-stroke of the eccentric may impart a high rate of speed to the plungers.

10. A fuel pump comprising a casing having cylinders in connection with a fuel supply and with the combustion chamber, plungers in the cylinders, means to drive the plungers, a check valve between the cylinders, a governor driven by the engine, and means moved by the governor for openin the check valve whereby to control the interval of injection in inverse proportion to the speed of the engine.

11. A fuel pump'comprising a casing in connection with a source of fuel supply and with the combustion chamber of a motor having a nozzle valve, pump plunger-s in the casing, a mechanically opened valve between the plungers adapted to permit an instantaneous drop of pressure in the fuel delivery nozzle whereby to effect an instantaneous and positive closing of the nozzle valve thereby eliminating the nozzle drip.

JOHN ERLE DOUGLAS. 

